Expanding reamer



Patented Sept. 23, 1924. 1,599,443

UNITED STATES PATENT OFFICE.

FRANK J. PETERSON, or swIssvALE, PENNSYLVANIA.

EXPANDING REAMER.

Application filed January 20, 1923. Serial No. 613,965.

To all whom it may concern: nally extending grooves 9 which increase in Be it known that I, FRANK J. PETERSON, depth from one end toward the other. a citizen of the United States, residing at Closely fitted into each groove is a key Swissvale, in the county of Allegheny and 10 which is tapered on its lower face to con- 5 State of Pennsylvania, have invented cerform to the inclination of the bottom of the s tain new and useful Improvements in Exgroove, the outer or top surface of each panding Reamers, of which the following key preferably being slightly rounded. is a specification. Each key is substantially shorter than the This invention is for an expanding length of the groove, and formed at each 1.0 reamer of the type having separable segend thereof is a barb 11 which slopes inmental utters, wardly toward the ends of the key, an ab- The invention has for its principal obrupt shoulder being provided at 12. ject to provide an expanding reamer of a The keys-are of the same width throughsimple construction, which may be ex out, and are of such size that when they are panded to its limit with a relatively high received in the grooves with their thickest degree of efficiency with respect to its norportions in the deepest portions of the mal or contracted status, and in which a grooves, their surfaces, with the exception very delicate and accurate expansion of the of the lugs or barbs 11, being substantially cutters may be effected, the cutters having flush with the surface of the mandrel, as 20 a fixed bearing surface on longitudinally shown in Fig. 2. l/Vhen they are moved movable members, whereby the cutters do along the groove, however, the co-engaging not shift their point of contact with the inclined faces of the keys and grooves force supporting members according to any them gradually outward, the outer faces of change of curvature which. accompanies the the keys always remaining parallel with expanding and contracting movements. the longitudinal axis of the mandrel;

The invention may be readily understood The cutters or bits are designated 13, and by reference to the accompanying drawings, are transversely curved, preferably to conin which: form substantially to the outer surface of Fig. 1 isa side elevationof the assembled the mandrel. There are preferably four tool in a vertical position; bits, and spiral teeth 14- are preferably pro Fig. 2 is a side view, partly in section, vided on the outer surface, although other of the tool, with-the cutters or bits removed, forms of teeth might, of course, be emshowing the parts in the contracted position ployed. Each end of the bits is beveled, for the cutters; as indicated at 15, and in the bevel portion 35 Fig. 3 is a substantially similar view, is alongitudinal notch 16. The bitsare of with the parts in expanded position; substantially the same length as the keys,

Fig. 4 is a transverse section through the and when the bits are applied to the mantool, with the cutters in contracted posidrel, the barbs or lugs 11 fit into the notches tion; 16, and thus hold the bit from rotationr'ela- 40 Fig. 5 is a similar view, with the reamer tively to the mandrel. expanded; At each end of the keys and slidable on i Fig. 6 is a plan view of one end of one the mandrel 1s a sleeve 17 having-a beveled of the'cutters or bits. 7 recess 18 therein adaptedtoreceive the bev- In the drawings, 5 designates a suitable eled or tapered ends of the keysand-bits,

45 mandrel having a squared chuck engaging and thereby hold the-parts assembled. Colend 6 and a shank 7. The mandrel is lars or nuts 19, threaded on the threaded threaded for a considerable portion of its part of the mandrel and having'wrench enlength between its ends, as designated at gaging surfaces 20 thereon, serve to hold the 8. In the threaded-portionof the mandrel, sleeves in hit engaging and retaining posi are a plurality, preferably four, longitudi tion. By loosening the nut at oneend of the tool and tightening the other, the bits and keys may be moved longitudinally, thereby forcing the keys, and consequently the cutters, radially outwardly or inwardly.

It will be noted that the outer face of the keys has substantially the same curvature as the inner face of the bits. As there is no relative movement between the bits and keys, the same surfaces are always in the same position of contact. The inner faces of the keys and of the grooves, being fiat, or being of the same conformation throughout, the keys always have the same area of contact With'the bottoms of the grooves at all times. This is of considerable advantage over that form of expanding reamer where the curved inner surface of the cutter engages directly a slot in the mandrel whose bottom is curved, because, in that form, the contacting surfaces conform when the cuttersare in one position only, and as the cutters are shifted longitudinally to effect expansion or contraction, the areaof contact between the groove and the cutter changes.

The present device, furthermore, is a cheaper and more simple device to machine or manufacture.

I claim as my invention:

1. An expanding reamer comprising a mandrel having series of longitudinal grooves therein whose depth increases from one end of the mandrel toward the other, a

series of segmental longitudinally extending bits, and a key on the under face of each bit and movable therewith engaging in a groove in the mandrel and slidable therein to adjust the bits to different positions, and means for holding the parts in the different positions to which they are adjusted.

2. An expanding reamer comprising a mandrel having a series of longitudinal grooves therein whose'depth increases from one end of the mandrel toward the other, a key slidable in each groove in the mandrel, a bit carried by each key and movable longitudinally therewith, means for adjustably retaining the keys and bits in place on the mandrel, and means whereby rotative movement of the mandrel is positively transmitted to the bits.

3. An expanding reamer comprising a mandrel, a groove of gradually increasing depth in the mandrel, a key of gradually increasing thickness slidable in the groove, the taper of the key being reversed to that of the groove,.a bit at whose inner surface the key is disposed and which is movable longitudinally with the key, said key and bit being held against relative longitudinal and rotative movement, and means for adjustably retaining the key and bit in position on the mandrel.

4. An expanding reamer comprising a mandrel having a groove of gradually increasing depth therein, a key of gradually increasing thickness slidablc in the groove, said key having lugs at the ends thereof projecting above the surface of the key, a bit resting on said key, which bit has notches therein to receive the lugs on the key for preventing relative movement between the key and bit, and means for adjustably retaining the key and bit in position on the mandrel.

5. An expanding reamer comprising a mandrel having a series of grooves of increasing depth therein, a key slidahle in each groove, the keys also being of gradually increasing thickness and being so disposed in the groove that their outer surfaces are substantially parallel with the longitudinal axis of the mandrel, ta ered lugs at the ends of the keys, a series 0 segmental bits resting on the keys and having notched tapered ends, the notches thereof receiving the lugs on the keys, and means adjustable longitudinally of the mandrel having a tapered recess for receiving the tapered ends of the keys and bits for adjust-- ably retaining the parts in position.

6. An expanding reamer comprising a mandrel, a series of detachable cutter segments, means interposed between the cutters and the mandrel having cooperatin engagement with the cutters and mandre and arranged to transmit motion from the mandrel to the cutter segments, said segments being longitudinally movable with said means, said means being movable longitudinally along the mandrel and so engaged therewith as to move radially with such longitudinal movement to correspondingly move the cutter segments, and means for adjustably retaining the parts in position.

7. An expanding reamer comprising a mandrel having grooves of increasing depth therein by reason of which the bottoms of the grooves are inclined, aseries of cutter bits having tapered ends, keys tapered reversely to the inclination of the grooves at the inner surface of the bits and engaging in the grooves in the mandrel, said ke s being attached to the bits and movable l ongitudinally therewith and adapted to move the cutter bits radially by longitudinal movement along said grooves, and means at each end of the bits having a tapered recess therein for receiving the tapered ends of said cutter bits to retain said bits in osition on the mandrel, said means being ongitudinally adjustable on the mandrel to retain the parts in different adjusted positions.

8. An expanding reamer comprising a mandrel having a series of grooves of increasing depth therein, a key slidable in each groove, the keys also being of gradually increasing thickness and being so disposed in the grooves that their outer surfaces are substantially parallel With the longitudinal axis of the mandrel, tapered lugs at the ends of the keys, a series of segmental bits resting on the keys and having notched tapered ends, the notches thereof receiving the lugs on the keys, a collar at each end of the cutters slidable on the mandrel, said collars having tapered recesses therein for receiving the tapered ends of 10 the cutters and keys and a nut disposed back of each collar and having a threaded engagement with the mandrel 'for adjustahly retaining the parts in position.

It testimony whereof I aflix my signature.

FRANK J. PETERSON. 

